Prevalence and main outcomes of placenta accreta spectrum: a systematic review and metaanalysis

OBJECTIVE: The objective of this study was to evaluate the prevalence of placenta accreta spectrum in general population studies and the main maternal outcomes at delivery. STUDY DESIGN: Data sources: We searched PubMed, Google Scholar, clinicalTrials.gov and MEDLINE between 1982 and 2018. STUDY ELIGIBILITY CRITERIA: Articles providing data on the number of cases of placenta accreta spectrum per pregnancies, births or deliveries in a defined population. STUDY APPRAISAL AND SYNTHESIS METHODS: Study characteristics were evaluated by two independent reviewers using a predesigned protocol. Primary outcomes were the prevalence of placenta accreta spectrum and clinical diagnostic at birth and pathologic criteria used to confirm the diagnosis. Secondary outcomes included cases requiring transfusion, incidence of peripartum hysterectomy and maternal mortality rates. Heterogeneity between studies was analysed with the Cochran's Q-test and the I2 statistics. RESULTS: Of the 98 full-text studies identified, 29 articles met the defined criteria including 22 retrospective and 7 prospective studies comprising 7,001 cases of placenta accreta spectrum out 5,719,992 births. Prevalence rates ranged between 0.01 and 0.1% with an overall pooled prevalence of 0.17% (95% CI 0.14-0.19). Only 10 studies provided with detailed histopathologic data. The pool prevalence for the adherent versus the invasive grades was 0.5 (95% CI 0.3-0.36) and 0.3 (95% CI 0.2-0.4) per 1000 births, respectively. The pooled incidence for peripartum hysterectomy was 52.2% (95% CI 38.3-66.4; I2= 99.8%) and 46.9% (95 % CI 34-59.9, I2= 98.8%) for haemorrhage requiring transfusion. The pooled estimate of maternal death was 0.05% (95% CI 0.06-0.69, I2=73%). We found large amounts of heterogeneity between studies for all parameters and further quantifying was limited because of methodological inconsistencies between studies with regards to clinical criteria used for the diagnosis of the condition at birth and the histopathologic confirmation of the diagnosis and differential diagnosis between adherent and invasive accreta placentation. CONCLUSIONS: This meta-analysis indicates wide variation between studies for the prevalence rate of placenta accreta spectrum and for the different grades of accreta placentation, highlighting the need for consistency in definitions used to describe placenta accreta spectrum at birth and in reporting on this increasing common obstetric complication

Ambient air pollution and adverse birth outcomes: A review of underlying mechanisms

Epidemiological data provide varying degrees of evidence for associations between prenatal exposure to ambient air pollutants and adverse birth outcomes (suboptimal measures of fetal growth, preterm birth and stillbirth). To assess further certainty of effects, this review examines the experimental literature base to identify mechanisms by which air pollution (particulate matter, nitrogen dioxide and ozone) could cause adverse effects on the developing fetus. It likely that this environmental insult impacts multiple biological pathways important for sustaining a healthy pregnancy, depending upon the composition of the pollutant mixture and the exposure window owing to changes in physiologic maturity of the placenta, its circulations and the fetus as pregnancy ensues. The current body of evidence indicates that the placenta is a target tissue, impacted by a variety of critical processes including nitrosative/oxidative stress, inflammation, endocrine disruption, epigenetic changes, as well as vascular dysregulation of the maternal‐fetal unit. All of the above can disturb placental function and, as a consequence, could contribute to compromised fetal growth as well increasing the risk of stillbirth. Furthermore, given that there is often an increased inflammatory response associated with preterm labour, inflammation is a plausible mechanism mediating the effects of air pollution on premature delivery. In the light of increased urbanisation and an ever‐changing climate, both of which increase ambient air pollution and negatively affect vulnerable populations such as pregnant individuals, it is hoped that the collective evidence may contribute to decisions taken to strengthen air quality policies, reductions in exposure to air pollution and subsequent improvements in the health of those not yet born

Epidemiology of placenta previa accreta: a systematic review and meta-analysis

Objective To estimate the prevalence and incidence of placenta previa complicated by placenta accreta spectrum (PAS) and to examine the different criteria being used for the diagnosis. Design Systematic review and meta-analysis. Data sources PubMed, Google Scholar, ClinicalTrials.gov and MEDLINE were searched between August 1982 and September 2018. Eligibility criteria Studies reporting on placenta previa complicated by PAS diagnosed in a defined obstetric population. Data extraction and synthesis Two independent reviewers performed the data extraction using a predefined protocol and assessed the risk of bias using the Newcastle-Ottawa scale for observational studies, with difference agreed by consensus. The primary outcomes were overall prevalence of placenta previa, incidence of PAS according to the type of placenta previa and the reported clinical outcomes, including the number of peripartum hysterectomies and direct maternal mortality. The secondary outcomes included the criteria used for the prenatal ultrasound diagnosis of placenta previa and the criteria used to diagnose and grade PAS at birth. Results A total of 258 articles were reviewed and 13 retrospective and 7 prospective studies were included in the analysis, which reported on 587 women with placenta previa and PAS. The meta-analysis indicated a significant (p<0.001) heterogeneity between study estimates for the prevalence of placenta previa, the prevalence of placenta previa with PAS and the incidence of PAS in the placenta previa cohort. The median prevalence of placenta previa was 0.56% (IQR 0.39–1.24) whereas the median prevalence of placenta previa with PAS was 0.07% (IQR 0.05–0.16). The incidence of PAS in women with a placenta previa was 11.10% (IQR 7.65–17.35). Conclusions The high heterogeneity in qualitative and diagnostic data between studies emphasises the need to implement standardised protocols for the diagnoses of both placenta previa and PAS, including the type of placenta previa and grade of villous invasiveness. PROSPERO registration number CRD4201706858

Stranding of a humpback whale (Megaptera novaeangliae) on the Belgian coast

peer reviewe

Post-mortem findings and causes of death of harbour porpoises (Phocoena phocoena) stranded from 1990 to 2000 along the coastlines of Belgium and northern France

peer reviewedBetween the,ears 1990 and 2000, an attempt was made to determine the causes of death of 55 harbour porpoises stranded along the Belgian and northern French coasts. From 1990 to 1996, only five carcasses were collected as against seven in 1997, eight in 1998, 27 in 1999 and eight in 2000. The sex ratio was normal and most of the animals were juvenile. The most common findings were emaciation, severe parasitosis and pneumonia. A few cases of fishing net entanglement were observed. The main microscopical lesions were acute pneumonia, massive lung oedema, enteritis, hepatitis and gastritis. Encephalitis was observed in six cases. No evidence of morbillivirus infection was detected. Pneumonia was associated with bacteria or parasites, or both. The causes of death and the lesions were similar to those previously reported in other countries bordering the North Sea. The cause of the increased numbers of carcasses in 1999 was unclear but did not include viral epizootics or net entanglement. A temporary increase in the porpoise populatiou in the southern North Sea may have been responsible. (C) 2002 Elsevier Science Ltd. All rights reserved

Mmf1p, a novel yeast mitochondrial protein conserved throughout evolution and involved in maintenance of the mitochondrial genome

A novel protein family (p14.5, or YERO57c/YJGFc) highly conserved throughout evolution has recently been identified. The biological role of these proteins is not yet well characterized. Two members of the p14.5 family are present in the yeast Saccharomyces cerevisiae. In this study, we have characterized some of the biological functions of the two yeast proteins. Mmf1p is a mitochondrial matrix factor, and homologous Mmf1p factor (Hmf1p) copurifies with the soluble cytoplasmic fraction. Δmmf1 cells lose mitochondrial DNA (mtDNA) and have a decreased growth rate, while Δhmf1 cells do not display any visible phenotype. Furthermore, we demonstrate by genetic analysis that Mmf1p does not play a direct role in replication and segregation of the mtDNA. rho(+) Δmmf1 haploid cells can be obtained when tetrads are directly dissected on medium containing a nonfermentable carbon source. Our data also indicate that Mmf1p and Hmf1p have similar biological functions in different subcellular compartments. Hmf1p, when fused with the Mmf1p leader peptide, is transported into mitochondria and is able to functionally replace Mmf1p. Moreover, we show that homologous mammalian proteins are functionally related to Mmf1p. Human p14.5 localizes in yeast mitochondria and rescues the Δmmf1-associated phenotypes. In addition, fractionation of rat liver mitochondria showed that rat p14.5, like Mmf1p, is a soluble protein of the matrix. Our study identifies a biological function for Mmf1p and furthermore indicates that this function is conserved between members of the p14.5 family

Perinatal Environmental Tobacco Smoke Exposure in Rhesus Monkeys: Critical Periods and Regional Selectivity for Effects on Brain Cell Development and Lipid Peroxidation

Perinatal environmental tobacco smoke (ETS) exposure in humans elicits neurobehavioral deficits. We exposed rhesus monkeys to ETS during gestation and through 13 months postnatally, or postnatally only (6–13 months). At the conclusion of exposure, we examined cerebrocortical regions and the midbrain for cell damage markers and lipid peroxidation. For perinatal ETS, two archetypal patterns were seen in the various regions, one characterized by cell loss (reduced DNA concentration) and corresponding increases in cell size (increased protein/DNA ratio), and a second pattern suggesting replacement of larger neuronal cells with smaller and more numerous glia (increased DNA concentration, decreased protein/DNA ratio). The membrane/total protein ratio, a biomarker of neurite formation, also indicated potential damage to neuronal projections, accompanied by reactive sprouting. When ETS exposure was restricted to the postnatal period, the effects were similar in regional selectivity, direction, and magnitude. These patterns resemble the effects of prenatal nicotine exposure in rodent and primate models. Surprisingly, perinatal ETS exposure reduced the level of lipid peroxidation as assessed by the concentration of thiobarbituric acid reactive species, whereas postnatal ETS did not. The heart, a tissue that, like the brain, has high oxygen demand, displayed a similar but earlier decrease (2–3 months) in lipid peroxidation in the perinatal exposure model, whereas values were reduced at 13 months with the postnatal exposure paradigm. Our results provide a mechanistic connection between perinatal ETS exposure and neurobehavioral anomalies, reinforce the role of nicotine in these effects, and buttress the importance of restricting or eliminating ETS exposure in young children

Genetic and historic evidence for climate-driven population fragmentation in a top cetacean predator: the harbour porpoises in European water

Recent climate change has triggered profound reorganization in northeast Atlantic ecosystems, with substantial impact on the distribution of marine assemblages from plankton to fishes. However, assessing the repercussions on apex marine predators remains a challenging issue, especially for pelagic species. In this study, we use Bayesian coalescent modelling of microsatellite variation to track the population demographic history of one of the smallest temperate cetaceans, the harbour porpoise (Phocoena phocoena) in European waters. Combining genetic inferences with palaeo-oceanographic and historical records provides strong evidence that populations of harbour porpoises have responded markedly to the recent climate-driven reorganization in the eastern North Atlantic food web. This response includes the isolation of porpoises in Iberian waters from those further north only approximately 300 years ago with a predominant northward migration, contemporaneous with the warming trend underway since the ‘Little Ice Age’ period and with the ongoing retreat of cold-water fishes from the Bay of Biscay. The extinction or exodus of harbour porpoises from the Mediterranean Sea (leaving an isolated relict population in the Black Sea) has lacked a coherent explanation. The present results suggest that the fragmentation of harbour distribution range in the Mediterranean Sea was triggered during the warm ‘Mid-Holocene Optimum’ period (approx. 5000 years ago), by the end of the post-glacial nutrient-rich ‘Sapropel’ conditions that prevailed before that time